The gas turbine engine is the preferred class of internal combustion engine for many high power applications. Fundamentally, the gas turbine engine features an upstream rotating compressor coupled to, and typically driven by, a downstream turbine, with a combustion chamber residing in-between the two rotary components. A torch igniter is a device that may be used to ignite the primary combustor of a gas turbine engine. In some applications, the torch igniter has advantages over conventional spark igniters, because it can provide larger amounts of energy release to the main combustor, and thus, is capable of lighting the engine in a more reliable manner. To achieve this, the torch igniter requires an auxiliary source of fuel and air, as well as an ignition source. Auxiliary air flow is typically obtained from the plenum downstream of the engine's compressor or from an external source of compressed air; and the auxiliary fuel is obtained from the fuel-metering unit or manifold or from an independent fuel source. Air flow requirements to operate the torch igniter may vary under different conditions, but are often significantly less than the air flow requirements of the primary combustor. On a typical engine, much like a conventional spark igniter, there can be two or more torch igniters for redundancy.